}

to be always true, because Zend_Db_Table_Rowset which is stored in $model here implements toArray() method. This method does this:

public function toArray()
{
// @todo This works only if we have iterated through
// the result set once to instantiate the rows.
foreach ($this->_rows as $i => $row) {
$this->_data[$i] = $row->toArray();
}
return $this->_data;
}

So all rows in rowset are converted to array.

The side effect of this behaviour is that: $this->partialLoop()->setObjectKey('myObject')->partialLoop($viewScript, Zend_Db_Table_Rowset $rowset);